1. Field of the Invention
The present invention relates to a radiometric measuring arrangement.
2. Background of the Invention
The current state of knowledge is as follows.
Various different radiometric measuring arrangements are known from the prior art, for the purpose of measuring fill levels, density, and point levels. A radioactive beam source and a detection device are arranged on opposite sides of a container or area being monitored, to make the measurement. Gamma radiation is emitted by the radioactive beam source, through the container, and in the direction of the detection device, and said gamma radiation is to a greater or lesser degree absorbed along its path through the fill material according to the fill level and density of the fill material. Based on the radiation intensity detected by the detection device, it is possible to make a deduction about the fill level or the density of a fill material positioned between the beam source and the detection device. A detection of the point level is also possible.
By way of example, in the case of a measurement of the fill level, a radiation intensity detected by the detection device is indirectly proportional to a fill level in the container, such that a fill level measurement is possible for goods which are high.
One particular advantage of radiometric fill level measurement is that the components which are necessary for the measurement—particularly the beam source and the detection device—can be arranged outside of a container, and therefore neither the process conditions inside the container nor the properties of the fill material has consequences for the applicability of these measurement methods.
In the radiometric measuring arrangements known in the prior, it is known that the detection device is designed as a scintillator having a photomultiplier connected behind the same, as a photosensitive element. The gamma radiation arriving at the scintillator material stimulates the same by collisions, wherein the scintillator material returns to its starting state, giving off light in the process. Conclusions can be made about the intensity of the arriving radiation, and therefore—as specified above—about a fill level inside the container, by way of example, by measuring the amount of light—by way of example, via the photomultiplier and an electronic measuring device connected downstream of the same. However, organic scintillator materials in particular—for example polymer solids—are extremely temperature sensitive, and must therefore not be stored or operated above a certain threshold temperature. By way of example, for polystyrene as the scintillator material, this threshold temperature is +50° C.
By way of further example, a longitudinally extended scintillator can be made in the form of a fiber bundle, using the scintillator materials named above, which then has the advantage that it can be adapted to various different container shapes. In particular, such a scintillator can be arranged, for example, on the outer wall of a tank which, for example, has a round form, an arrangement which is very highly prized for the purpose of achieving a compact construction of the measuring arrangement. A particular advantage is that, due to the flexibility of the scintillator, there is also a high flexibility in use, and it is possible to avoid the production of a plurality of differently shaped scintillators—for example adapted to different tank shapes.
However, the spectrum of application of such scintillators is limited according to the ambient conditions, and particularly temperature, which is a disadvantage.
And this is where the present invention comes in. The problem addressed by the invention is that of further advancing a radiometric measuring arrangement, having a longitudinally extended, flexible scintillator, in such a manner that the same can be used independently of the prevailing ambient conditions, without losing its existing advantages.